The Codex Borgia is among the best-preserved pre-Hispanic codices. It contains a series of mythical narratives that detail the sequential yearly religious festivals.

The Borgia is the namesake for the Borgia Group, a corpus of codices similar in their origin, style, and content. They come from the Mixteca region of Mexico, which encompasses the states of Puebla, Guerrero, and Oaxaca. Principally, they serve as “divinatory manuals,” containing information about astronomy, astrology, and mythology. These overlap, with deities often representing celestial bodies. These texts are comparable, at least superficially, to astrological traditions in the West.

Recent scholarship suggests the Borgia itself has various scientific imports. For example, ethnoastronomer Susan Milbrath observes that the Borgia contains a unique depiction of Quetzalcoatl in his role as the “Evening Star” (Venus) seen nowhere else. On the page above in the upper-left quadrant (and again in the center-right position) (folio 35), you will notice that he has a “smoky eye,” theoretically representing a comet that would (a) be visible in Mexico that year and (b) indeed appear in the eastern sky adjacent to Venus.